remover o primeiro caracter de uma string javascript

JavaScript
var string1 = "foobar";
var string2 = string1.substr(1);
console.log(string2); // shows "oobar"

var string = "//www.pipi.com";
while(string.charAt(0) === '/') { //take character position 0
   string = string.substr(1);
}
Source

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